<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
</head>
<body>
		<div>hello</div>
</body>
<script >
		var div = document.querySelector("div");
		Object.prototype.css = function(styleName,styleValue){
			this.style['styleName'] =styleValue;
			return this;
		}
		div.css('width','100px').css('height','100px').css('backgroundColor','red');

</script>
</html>